﻿// UVa11988 Broken Keyboard
// Rujia Liu
#include<cstdio>
#include<cstring>
const int maxn = 100000 + 5;
int last, cur, next[maxn]; // 光标位于cur号字符之后面
char s[maxn];

int main() {
	while (scanf("%s", s + 1) == 1) {
		int n = strlen(s + 1); // 输入保存在s[1], s[2]...中
		last = cur = 0;
		next[0] = 0;

		for (int i = 1; i <= n; i++) {
			char ch = s[i];
			if (ch == '[') cur = 0;
			else if (ch == ']') cur = last;
			else {
				next[i] = next[cur];
				next[cur] = i;
				if (cur == last) last = i; // 更新“最后一个字符”编号
				cur = i; // 移动光标
			}
		}
		for (int i = next[0]; i != 0; i = next[i])
			printf("%c", s[i]);
		printf("\n");
	}
	return 0;
}
